This invention relates to electromagnetic projectile launchers and more particularly to such launchers which include structures for recovering inductively stored rail energy or for accelerating projectile rail current decay following the launch of a projectile.
In parallel rail electromagnetic projectile launcher systems, muzzle shunting circuitry has been proposed for the purpose of dissipating inductive energy which remains stored in the rail bore length just after projectile exit. This muzzle shunting circuitry may include a muzzle shunt resistor which is connected across the rails such that most of the post-firing rail inductive energy is dissipated in the resistor rather than in an arc at the muzzle ends of the rails. Dissipating energy in a resistor reduces the fraction of post-firing energy which must be dissipated by the projectile rails and hence reduces rail temperatures, reduces rail cooling requirements or allows more shots to be fired without attaining excessive rail temperatures.
My copending commonly assigned application, Ser. No. 564,050, filed Dec. 21, 1983 and entitled "Electromagnetic Launcher with Improved Rail Energy Recovery or Dissipation" discloses muzzle shunting circuitry which includes conductors which lie parallel to the launcher rails and which are folded toward the breech end of the rails from their attachment points near the muzzle end of the rails. The muzzle shunting loop may be resistive to dissipate the rail inductive energy or may contain switching elements to usefully recover a fraction of that energy. Since the muzzle shunting loop is electrically attached to the launcher rails near the muzzle, premature and parasitic muzzle loop current flow may have to be impeded by a series switching means in launchers where a significant muzzle voltage appears during projectile acceleration, for example, in arc-driven launchers. Application Ser. No. 564,050 includes additional background material and is hereby incorporated by reference.